The present invention relates to a hollow cylindrical member mainly made of synthetic resins, and more particularly to a hollow cylindrical member which contains a metallic material in the synthetic resins for reinforcing property and/or decorative property and which is applicable to a golf club shaft, a fishing rod, a bicycle frame, a ski stock or the like.
Japanese Patent Unexamined Publication No. Hei. 3-61030 discloses a hollow cylindrical member which is formed of a wound preimpregnation material sheet made of high-strength fibers impregnated with synthetic resins and which is provided with a reinforcing metal layer on an outer surface of the hollow cylindrical member.
In the disclosed hollow cylindrical member, a metal wire to which thread having good bonding property with matrix is wound, is spirally or twillingly wound onto a laminated main body of the wound preimpregnation material sheets in order to enhance the strength of the hollow cylindrical member and to attain close bonding between component parts.
However, the hollow cylindrical member has a disadvantage in that in spite of exhibiting large irregular portions, i.e. projections or recesses due to the provision of the metallic wire, exposed portions of the laminated main body becomes still large in area so that these exposed portions are likely to be cracked, damaged, worn out and broken.
Further, the metallic wire has many projecting portions and the contact area between the metallic wire and the laminated main body is small, so that the metallic wire is likely to be peeled off from the laminated main body even if the material having good bonding property is provided around the metallic wire.
Japanese Patent Unexamined Publication No. Hei. 2-98376 discloses another type of a hollow cylindrical member which is formed by laminating fiber-reinforced resins and which contains therein a metallic layer in order to enhance decorative value, surface hardness and impact-resistance of a golf club shaft.
In the disclosed hollow cylindrical member, a preimpregnation material sheet utilizing a woven fabric as a reinforcing material and having a thin metallic film applied to one side surface thereof, is wound onto an inner layer such that the metallic film is disposed at the inside of the hollow cylindrical member, so that the metallic film is obstructed by fiber-intersecting points of the reinforcing woven fabric, resulting in that the metallic glossy generated by the metallic film becomes shaded and uneven. Further, the metallic film is adversely influenced by the carbon fibers used as the reinforcing material in the inner layer, so that metallic glossy is unavoidably blackened and muddied. Therefore, the sufficient ornamental or decorative effect cannot be produced due to these arrangement.